Index fund is the best investment tool for regular investment. Among all kinds of securities investment funds, which one is the most suitable for regular investment? Let's analyze the starting point and advantages of regular fixed investment. First, from the perspective of investment volatility, index funds are suitable for regular fixed investment. As a passive investment tool, index fund is a typical product that depends on the weather, and its indexed investment income strictly follows the market fluctuation. This highly volatile investment product can reduce the risk through regular fixed investment, and the effect of fixed investment is the best. However, other investment tools with low volatility, such as bond funds and money market funds, can not give full play to the advantages of fixed-term investment, and their long-term investment income is not attractive. Second, from the perspective of investment discipline, index funds are also suitable for regular fixed investment. The purpose of regular fixed investment is to avoid chasing up and down through the discipline of investment timing. Compared with the securities selection discipline, index fund is the strongest fund product in the investment discipline, and it constructs the investment portfolio strictly according to the target index. Combining regular fixed investment with index funds can strictly enforce investment discipline from two aspects: timing and securities selection, and achieve complementary investment effects. Other active investment products (such as actively managed stock funds) are greatly influenced by the subjective investment management of fund managers, and the stock position may be relatively low at the low point of the market, which can not achieve the effect of diluting the investment cost. Third, index funds have stable long-term returns and are investment tools for sharing economic growth. From the analysis of historical data of various securities markets, it can be seen that from the perspective of long-term investment, the rate of return of indexed investment is considerable and obviously higher than the growth of GDP on the premise that a country's economy maintains appropriate growth. For example, the average GDP growth rate of the United States in the past 20 years is 5. 1%, and S &；; The average yield of p500 index in recent 20 years is10.5%; The average growth rate of GDP in France in recent 20 years is 4. 1%, and the average yield of CAC40 index in France in recent 20 years is 1 1.6%. Third, regular fixed investment can also be the core-some fund investors in satellite asset allocation are unwilling to obtain indexed long-term investment returns, hoping to obtain certain excess returns on the basis of indexed investment. Such investors can refer to the common and practical core of foreign pension investment-satellite asset allocation method. Ordinary individual investors can also build their own core satellite portfolio. The simplest and most direct way is to invest some assets (such as half) in index funds, and the rate of return of index funds is the average rate of return of the whole market. Of course, if you are not satisfied with the average market return brought by index funds, investors can allocate funds other than index funds as satellite investments to 2-3 active funds in order to have the opportunity to obtain excess returns. The core satellite investment method organically combines active strategy and passive strategy, and integrates the advantages of passive investment, such as low cost, low risk, long-term stable income and active investment, so as to obtain excess income opportunities.